1. Field of the Invention:
The present invention relates to an insulating multiple glazed window unit for replacing single glazing in window openings. More particularly, the present invention relates to a novel method of constructing and installing a replacement multiple glazed window unit in an older single glazed window. The method accomplishes the retro fitting of older single glazed window sashes without removing the original window frame and sash and without destroying the aesthetics of the original window.
2. Description of the Prior Art:
Many existing buildings are constructed using single glazed windows which were installed in a era when energy efficiency and noise reduction were minor considerations at best. With the increased emphasis on energy efficiency in recent years, double glazed windows have become the norm and single glazed windows have become a renovation problem in older buildings. Often the single glazed windows are replaced with newly manufactured double paned windows that are expensive and do not duplicate the style of the older windows, significantly altering the aesthetics of the building. Thus, there is a long felt need for a reliable method to improve the energy efficiency and noise characteristics of older windows inexpensively and in a manner that preserves the aesthetics of the original window.
The prior art includes examples of various structures and methods which are intended to bring the benefits of insulating glass to existing single glazed window openings. The following listed patents are illustrative of these attempts:
______________________________________ Patent No. Patentee ______________________________________ 2,177,001 Owen 3,299,591 Woelk 3,971,178 Mazzoni et al 4,074,480 Burton 4,194,331 Gingle et al 4,357,187 Stanley et al 4,494,342 Decker 4,499,703 Rundo 4,719,728 Erikkson et al ______________________________________
All of the above patents disclose methods which utilize the technique of adhering an additional glazing spaced a distance from the existing glazing without removing the window pane from the frame and the construction site. Some require removal of the window sash but, all require mechanical aptitude and skill for the on-site assembly of the additional glazing. All of the patents listed lack methods to insure the interior cleanliness of the glazing or the integrity of the glazing seal and all retain the existing glazing in place. The glazing often lacks the characteristics of modern glass which include improved strength, clarity and modern energy coatings. Additionally, the construction methods taught by these prior art patents have not been demonstrated to satisfy energy code requirements.